[Elecraft] K2 and the KPA100 Power Fluxuates?

[Ron D'Eau Claire]

I've experienced that too, but I've been swamped and haven't had time to
pursue it. A buddy and fellow Elecraft owner, Lou, W7HV, sent me this =
info
about the problem:
--------------
If you haven't done this already, it's easy to check to see if the ALC =
is
causing the steps.  Pin 2 of U8 on the control board is the ALC control.
It's 8 bits out of 5V so an LSB is .02 volts.  If you see .02V changes
correlating with your power jumps, then that's it. =20
=20
Increasing R98 on the RF board reduced ALC gain so the effective =
resolution
of the DAC goes up.  Just make sure that the ALC output isn't saturated =
at
full power  on 10m (without the KPA installed).  I increased R98 to =
1.33K
and got 4V out of the DAC at 10W on 10m.  Valc (output of Q8 on the =
control
board) was 6.3V.  Valc maxes out at 7.5V so I had about 1.2V of head =
room.
=20
I believe there is a tech note about this on the Elecraft website =
somewhere.
-------------

Ron AC7AC
K2 # 1289

-----Original Message-----
I raised this question when I first built my KPA100.  On my unit at a =
set
20W output the power fluctuates between 17 - 22W.  This makes it very
difficult to set the SWR bridge pots for example in the KAT100....

Mike VP8NO (IOTA SA-002)
GQRP 10148
QRP-Canada #57
K2/100 #1400